This invention relates to porous compositions particularly useful as catalysts and catalyst supports. The compositions contain fibrous clays and have a large fraction of the pore volume present in 200 to 800 Angstrom diameter pores. The compositions of this invention are particularly useful as catalysts or catalyst supports for use in the conversion of hydrocarbonaceous feedstocks, such as crude petroleum and petroleum fractions, liquefied coal, shale oils, oils from bituminous sands (e.g., tar sands), etc., and hydrocarbonaceous fractions derived therefrom. The compositions are particularly useful for hydroprocessing heavy hydrocarbonaceous fractions which contain asphaltenes. The term "asphaltenes" as used herein refers to hydrocarbonaceous material which is insoluble in hot n-heptane, e.g., boiling at atmospheric pressure.
Naturally-occurring and synthetic clays have been suggested as catalysts for a variety of hydrocarbon conversions. Wegner et al. in U.S. Pat. No. 4,006,077, issued Feb. 1. 1977, discloses the use of extruded and dried attapulgite clays for removing metals from a hydrocarbon feed. Inooka et al. in U.S. Pat. No. 4,152,250, issued May 1, 1979, and U.S. Pat. No. 4,196,102, issued Apr. 1, 1980, disclose catalysts containing sepiolite fibers which can be bound together with oxide sols. Fukui et al. in U.S. Pat. Nos. 4,166,026 and 4,191,636 disclose a two-step hydrodemetalation and hydrodesulfurization process wherein the support for the hydrodemetalation catalyst is a magnesium silicate such as sepiolite, attapulgite and palygorskite. Hydroprocessing catalysts containing other clays are mentioned in Oleck et al., U.S. Pat. No. 3,891,541, issued June 24, 1975.
A disadvantage of prior art fibrous clay catalysts is that only a small fraction of their pore volume is present in pores in the 50 to 150 Angstrom diameter range which is known to be desirable in hydrodesulfurization catalysts. In addition, the addition of catalytic metals to fibrous clays to form a uniform dispersion is difficult, often resulting in the formation of crystalline compositions such as cobalt molybdate which generally have a lower catalytic activity.